In a cellular system, when the number of mobile station apparatuses accommodated in a given base station apparatus (that is, mobile station apparatuses with which the base station apparatus has established radio link connections) increases and thereby traffic is concentrated (hereinafter, a base station apparatus in such a condition will be referred to as a “high traffic base station apparatus”), the high traffic base station apparatus may distribute, when accommodating a new mobile station apparatus, the load by forcibly causing any one of the accommodated mobile station apparatuses to perform handover (for example, Patent Document 1). However, as a result, the reception quality of the mobile station apparatus which is forced to perform handover may deteriorate. In such a case, the throughput of the mobile station apparatus forced to perform handover deteriorates.
By the way, a multicarrier scheme which is represented by an OFDM (Orthogonal Frequency Division Multiplexing) scheme and has strong resistance to interference and fading is becoming a focus of attention in recent years. The multicarrier scheme allows any one of a plurality of subcarriers to be allocated to a given mobile station apparatus and allows other allocated subcarriers to be allocated to other mobile station apparatuses. That is, in a cellular system based on a multicarrier scheme, a high traffic base station apparatus can deallocate subcarriers of relatively low reception quality out of subcarriers allocated to the already accommodated mobile station apparatus and allocate the deallocated subcarriers to a new mobile station apparatus. By this means, it is possible to reduce a decrease of throughput of the mobile station apparatus for which some subcarriers have been deallocated.
Patent Document 1: Japanese Patent Application Laid-Open No. HEI10-51836